Question

The flame of the candle has three zones. The outer zone is blue, the middle zone is yellow and the inner zone is black. Which is correct regarding this?

• A. The outer zone is least hot
• B. The middle zone is hottest
• C. The inner zone is least hot
• D. All the zones have same temperature

Answer 1

The correct option is C The inner zone is least hot

The hottest part of the flame is the outer zone with blue color which has the highest temperature due to complete combustion, the yellow part of the flame has a temperature less than the outer part.

While the innermost zone is black in color which has the least temperature. This black color is due to unburnt wax vapors. So as the distance of the flame from the centerline increases the temperature increases.

Hence, option $C$ is correct.